Thanks for your comments.
You are free to improve the shadows use a bias for the depthcomparison and choose a higher depthmap depth (instead of 16bit floatingpoint per channel 32 bit fp per channel, 12222 -> 14444) It looks much better than but needs a strong hardware... (the higher shadowmap resolution and pixeldepth caused the first demos to have such really hard displayingproblems on "older" hardware)